Fix for mailto: URLs containing a + sign. Thanks to Michael Puls II for the patch.

doc/ChangeLog

@@ -326,6 +326,8 @@ Version 1.5.2 - SVN
   - Implemented security token system. (Secunia Advisory SA34627)
   - Fix issue with multi-part related messages not showing all attachments (#2830140).
   - Fix for security token missing in newmail plugin (#2919418).
+  - Fix for mailto: urls containing + characters, thanks to Michael Puls II for the 
+    patch.
 
 Version 1.5.1 (branched on 2006-02-12)
 --------------------------------------

functions/url_parser.php

@@ -146,9 +146,15 @@ function parseUrl (&$body) {
             if ((preg_match($MailTo_PReg_Match, $mailto, $regs)) && ($regs[0] != '')) {
                 //sm_print_r($regs);
                 $mailto_before = $target_token . $regs[0];
-                $mailto_params = $regs[10];
+                /**
+                 * '+' characters in a mailto URI don't need to be percent-encoded.
+                 * However, when mailto URI data is transported via HTTP, '+' must
+                 * be percent-encoded as %2B so that when the HTTP data is
+                 * percent-decoded, you get '+' back and not a space.
+                 */
+                $mailto_params = str_replace("+", "%2B", $regs[10]);
                 if ($regs[1]) {    //if there is an email addr before '?', we need to merge it with the params
-                    $to = 'to=' . $regs[1];
+                    $to = 'to=' . str_replace("+", "%2B", $regs[1]);
                     if (strpos($mailto_params, 'to=') > -1)    //already a 'to='
                         $mailto_params = str_replace('to=', $to . '%2C%20', $mailto_params);
                     else {